Numbers n such that string 7,8 occurs in the base 9 representation of n but not of n+1.

Terms

a(0) =71a(1) =152a(2) =233a(3) =314a(4) =395a(5) =476a(6) =557a(7) =647a(8) =719a(9) =800a(10) =881a(11) =962a(12) =1043a(13) =1124a(14) =1205a(15) =1286a(16) =1376a(17) =1448a(18) =1529a(19) =1610a(20) =1691a(21) =1772a(22) =1853a(23) =1934a(24) =2015a(25) =2105a(26) =2177a(27) =2258a(28) =2339a(29) =2420